Selemdzha

a river in Amur Oblast, RSFSR, the chief tributary of the Zeia, from the left. The Selemdzha is 647 km long and drains an area of 68,600 sq km. It originates at the junction of the Iam-Alin’ and Ezop mountain ranges. The upper course has the character of a mountain river; below the settlement of Ekimchan the valley widens, and the lower course flows along the northern edge of the Zeia-Bureia Lowland. The chief tributaries are the Ul’ma (on the left) and the Nora (on the right). The Selemdzha is fed primarily by rain. The mean flow rate is 715 cu m per sec, with a maximum of 10,300 cu m per sec in July and a minimum of 5 cu m per sec in March. The river freezes in early November, and the ice breaks up in early May. The Selemdzha is navigable as far as the mouth of the Nora; during high water, navigation is possible as far as Ekimchan. There are deposits of gold along the upper course.